Data Link Status - Omron SYSMAC LINK C1000H-SLK21-V1 System Manual

Data Link Status

5-9

Data Link Status

Node Status
Programming Example
60
The operational status of the data links in operating levels 0 and 1 is indicated in
the data link operating flags. SR 25202 is turned ON when a data link is active in
operating level 0 and SR 25205 is turned ON when a data link is active in operat-
ing level 1. These flags and corresponding SR bits are shown below.
SR bit
25202 Operating Level 0 Data Link Operating Flag
25205 Operating Level 1 Data Link Operating Flag
In addition to the overall operational status of the data link, the status of any node
involved in data link operations can be checked from any other node included in
data link operations. The Data Link Status Flags are contained in SR 238 to
SR 245 when data link tables are generated automatically. The user selects the
location of the data link status flags in the refresh parameters when data link
tables are generated manually.
Note 1. If the Data Link Operating Flag for the local node is OFF, the data link status
will remain the same as the status right before the data link was stopped.
Therefore, there is no guarantee that other status information will be correct.
When using the data link status, make sure that the Data Link Operating
Flag for the local node is ON.
2. The Data Link Operating Flag for other nodes and PC Operating Flags are
used to confirm that the system has been properly started. These flags
alone cannot be used to detect communications errors. To detect commu-
nications errors, use the Communications Error Flag and PC Error Flag. The
operation of each flag is described in the following table.
Flag
Data Link Operating
Flag for local node
PC Operating Flag
PC Error Flag
Communications Error
Flag
Data Link Operating
Flag for other nodes
Programming examples using data link status are shown below for the C200H,
C200HS, and C200HX/C200HG/C200HE.
Checking Data Link Participation of Other Nodes
As shown below, use an AND condition of a NO input of the Data Link Operating
Flag
Flag operation
ON when the local node is participating in the data links.
When this flag is OFF, data link communications will not
be performed properly., and there is no guarantee that
other status information is correct.
ON when the PC in the node is operating. This flag
operates according to data sent from the remote node
and is thus valid only when the Communications Error
Flag is OFF.
ON when an error (fatal error or watchdog timer error)
has occurred in the PC. This flag operates according to
data sent from the remote node and is thus valid only
when the Communications Error Flag is OFF.
ON when data link data is not received continually from
the subject node due to a disconnection or other cause.
The flag will turn OFF when data is received properly
from the remote node.
ON after the remote node properly participates in the
data links. The flag will remain ON even after the remote
node ends participation in the data links.
Section 5-9